Merge commit 'be3e8236086165e5e45a5a10783823874b3f3ebd' as 'lib/vscode'

lib/vscode/src/vs/base/common/uint.ts

@@ -0,0 +1,59 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+export const enum Constants {
+	/**
+	 * MAX SMI (SMall Integer) as defined in v8.
+	 * one bit is lost for boxing/unboxing flag.
+	 * one bit is lost for sign flag.
+	 * See https://thibaultlaurens.github.io/javascript/2013/04/29/how-the-v8-engine-works/#tagged-values
+	 */
+	MAX_SAFE_SMALL_INTEGER = 1 << 30,
+
+	/**
+	 * MIN SMI (SMall Integer) as defined in v8.
+	 * one bit is lost for boxing/unboxing flag.
+	 * one bit is lost for sign flag.
+	 * See https://thibaultlaurens.github.io/javascript/2013/04/29/how-the-v8-engine-works/#tagged-values
+	 */
+	MIN_SAFE_SMALL_INTEGER = -(1 << 30),
+
+	/**
+	 * Max unsigned integer that fits on 8 bits.
+	 */
+	MAX_UINT_8 = 255, // 2^8 - 1
+
+	/**
+	 * Max unsigned integer that fits on 16 bits.
+	 */
+	MAX_UINT_16 = 65535, // 2^16 - 1
+
+	/**
+	 * Max unsigned integer that fits on 32 bits.
+	 */
+	MAX_UINT_32 = 4294967295, // 2^32 - 1
+
+	UNICODE_SUPPLEMENTARY_PLANE_BEGIN = 0x010000
+}
+
+export function toUint8(v: number): number {
+	if (v < 0) {
+		return 0;
+	}
+	if (v > Constants.MAX_UINT_8) {
+		return Constants.MAX_UINT_8;
+	}
+	return v | 0;
+}
+
+export function toUint32(v: number): number {
+	if (v < 0) {
+		return 0;
+	}
+	if (v > Constants.MAX_UINT_32) {
+		return Constants.MAX_UINT_32;
+	}
+	return v | 0;
+}